1. Field of the Invention
The present invention relates to switches and, more specifically, to vehicle steering column mounted switches for controlling vehicle operating circuits and components.
2. State of the Art
The evolution of steering column switches in motor vehicles has been toward greater integration of functions in a single switch lever. Previously, a plurality of individual switches, each controlling a single vehicle function, i.e., turnsignals, windshield wipers, headlights, etc., were mounted on the vehicle dashboard. Current steering column switch levers are designed to control a variety of functions for vehicle operating circuits or devices, such as turnsignals and hazard lights, high beam and low beam headlights with optional flash-to-pass, parking lights, fog lights, windshield wiper and wash functions, including multi-speed wipers with or without intermittent delay.
Typically, a steering column stalk switch includes a single lever or stalk pivotally mounted on one side of a housing attached to the vehicle steering column in an easily accessible position for access by the driver of the vehicle. The lever is gimballed at one end in housing so as to move in one and, typically, two mutually separate planes. Further, the lever may be provided with a rotatable end cap, and/or a slidable member movable along the longitudinal axis of the lever to control additional vehicle operating circuits. An intermediate member on the lever may also be rotatable to control another vehicle circuit or device. Actuators are mounted in the housing and, in response to movement of the lever in different directions or planes, rotation of the end cap, or movement of the slidable member, or rotation of the intermediate member on the lever, move a switching member carrying contacts between various switching positions to effect the switching of electrical connections for a particular vehicle operating circuit.
In some vehicles, particularly vehicles manufactured in Europe and/or Japan, two steering column stalk switches are provided, one mounted on the left side of the steering column and one on the right side of the steering column. The various vehicle operating circuits or devices described above are split between the two stalk switches, with the left stalk switch typically controlling vehicle headlight, parking light, fog light, flash-to-pass operation as well as turnsignal operations. The right mounted stalk lever typically controls windshield wiper, mist and wash devices.
However, regardless of whether one or two stalk switches are employed in a vehicle, vehicle design constraints require that the stalk switch lever and the housing assembly be as small as possible while at the same time providing easy access to and movement of the various switches on the stalk switch(es). At the same time, each stalk switch must meet further design constraints relating to a low manufacturing cost, a minimal number of individual components, ease of assembly, and ease of installation in the vehicle. Such stalk switches must also have the capability of easy modification to different vehicle design parameters, such as the ability to control when the vehicle fog lights are operable with respect to the state of the vehicle high beam or low beam headlights. It would also be desirable to provide a vehicle mounted steering column stalk switch which is capable of three modes or degrees of motion, namely, radially, axial and gear driven to operate a plurality of electrical circuits in the vehicle. It would also be desirable to provide a vehicle mounted steering column stalk switch which has the capability of operating a plurality of auxiliary circuits in a single stalk switch lever.
A switch apparatus for operating a plurality of electrical circuits, such as electrical circuits in a vehicle wherein the switch apparatus is mounted in a vehicle stalk switch.
The present apparatus includes a housing mountable on a vehicle steering column. A pivot shaft is carried in the housing. A carrier is pivotally mounted on the pivot shaft for rotation about an axis through the shaft. A lever is pivotally mounted to the carrier for rotation about a first axis. A rotatable end cap is mounted on the lever. A shaft extends through the lever and is fixed to the end cap at a first end. A gear is mounted on the second end of the shaft and engages a radial toothed rack rotatably mounted in the housing. Electrical traces are formed on one of the radial toothed rack and the housing and coupled to electrical circuits. Electrical contacts are carried on the other of the radial toothed rack and the housing and selectively engagable with certain electrical traces upon rotation of the radial toothed rack.
According to one aspect of the present invention, the conductive traces are mounted in a grid member disposed in the housing. An actuator is at least rotatably and preferably, also translatingly mounted on the pivot shaft. The actuator has an arm extending outward from a center. A first leaf contact is carried on the grid member. A second leaf contact is also carried on the grid member and spaced from an opposed conductive trace in the grid member. The lever engages the actuator for translating the actuator along the pivotal shaft to electrically connect the first leaf contact with a contactor carried on the actuator upon translation of the actuator. The actuator is also coupled to the radial rack to rotate the rack upon rotation of the actuator. The arm on the actuator is engagable with the second leaf contact upon rotation of the actuator to disengage the leaf contact from one conductive trace on the grid member.
The present switch apparatus for actuating a plurality of electrical circuits affords several advantages over previously devised switch apparatus which form a part of a vehicle stalk switch assembly. First, the actuator provides several switching functions thereby affording the ability to control several vehicle operating circuits and/or devices via a one piece member which is responsive to pivotal movement of the lever about two distinct axes. In this manner, a plurality of electrical circuits are controlled by the present switch apparatus which is constructed with a reduced number of separate components and electrical interfaces as compared to previously devised vehicle steering column switch apparatus. The leaf contacts are insert molded into the grid member for further reduction in part count and electrical interfaces.